Transcriptional regulation is a major event in cell differentiation, proliferation and apoptosis. Transcriptional activation of a set of genes determines cellular function and is tightly regulated by a variety of factors. One of the regulatory mechanisms involved in this process is an alteration in the tertiary structure of DNA, which affects transcription factors to their target DNA regiments. Nucleosomal integrity is regulated by the acetylation status of the core histone, with the result being permissiveness to transcription. The regulations of transcription factor are thought to involve changes in the structure of chromatin. Changing the affinity of histone proteins for coiled DNA in the nucleosome alters the structure of chromatin. Hypoacetylated histones are believed to have greater affinity to the DNA and form a tightly bound DNA-histone complex and render the DNA inaccessible to transcriptional regulation. The acetylating status of the histone is governed by the balanced activities of the histone acetyl transferase (HAT) and histone deacetylase (HDAC). The bromodomain and extraterminal family of proteins called as BET proteins are readers of the acetyl status of histone and changes the chromatin structure and gene expression.
The BET family of bromodomain containing proteins comprises four proteins, namely BRD2, BRD3, BRD4 and BRDT, which are widely expressed in various tissues, except BRDT which is localized in the testes. Each of the BRD proteins contains tandem bromodomains capable of binding to acetylated lysine residues in histones H3 and H4. It has been reported that BRD2 and BRD3 are associated with histones along actively transcribed genes and involved in facilitating transcriptional elongation (Leroy et al, Mol. Cell. 2008 30(1):51-60), while BRD4 appears to be involved in the recruitment of the pTEF-[beta] complex to nuclesomes, which results in phosphorylation of RNA polymerase II and increases the transcriptional elongation of neighboring genes. (Hargreaves et al, Cell, 2009 138(1): 129-145).
BRD4 or BRD3 may fuse with NUT (nuclear protein in testis) forming novel fusion oncogenes, BRD4-NUT or BRD3-NUT, in a highly malignant form of epithelial neoplasia (French et al. Cancer Research, 2003, 63, 304-307 and French et al. Journal of Clinical Oncology, 2004, 22 (20), 4135-4139). Data suggests that BRD-NUT fusion proteins contribute to carcinogenesis (Oncogene, 2008, 27, 2237-2242). A BET protein which includes BRD4 have been shown to be important regulators of gene expression profiles in numerous diseases such as cancer, diabetes, obesity, cardiovascular and renal disorders. Currently several BRD4 inhibitors is in various stages of clinical trial for cancer such as IBET-762, JQ1, OTX-015 and RVX-2135 (P. Filippakopoulos, et. al., Nature Review Drug Discovery, 13, 2014, 337-356, M. Brand, et. al., ACS Chem. Biol, 10, 2015, 22-39).

A tricyclic aryl compound as squalene synthase inhibitors has been disclosed in WO2008133288 for the treatment of hypercholesterolemia, hypertriglyceridemia and hypo-HDL cholesterolemia and/or arteriosclerosis.

Masanori Ichikawa et. al published a paper (ACS Med. Chem. Lett., 2013, 932-936) describing the squalene synthase inhibitors DF4611 (B) and also Nils Griebenow, et. al. published a paper (Bioorg. Med. Chem. Lett. 21, 2011, 3648-3653) on the synthesis of novel 4H,6H-[2]benzoxepino[4,5-c][1,2]oxazoles (C) as squalene synthase inhibitors.

Although, there are several chemotherapies and target therapies based drugs for cancer, an effective cure for cancer still remains elusive. Further, development of acquired resistance and disease relapse are major issues that still need to be addressed. Even though several bromodomain inhibitors are known in the clinic as well as in the preclinic, still remains a need for finding potent bromodomain inhibitors having desirable drug like properties.
Therefore, the present invention provides novel and drug like molecules having good potency as BRD4 inhibitors which can inhibit the binding of acetylated lysine residue of histone for controlling gene expressions in various diseases.